24419 version 1

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Inspect and repair foundation (drum) brakes on heavy vehicles and machines

Level / 3
Credits / 3

PurposeThis unit standardis for peoplein the automotive heavy repair industry. People credited with this unit standard are able to inspect and repair drum brakes on heavy vehicles and machines.

Subfield / Motor Industry
Domain / Vehicle Braking Systems
Status / Registered
Status date / 25 January 2008
Date version published / 25 January 2008
Planned review date / 31 December 2012
Entry information / Recommended: Unit 24418, Demonstrate knowledge of foundation (drum) brakes on heavy vehicles and machines, or demonstrate equivalent knowledge and skills.
Replacement information / This unit standard, unit standard 24407, and unit standard 24418 replaced unit standard 15475.
Accreditation / Evaluation of documentation and visit by NZQA and industry.
Standard setting body (SSB) / NZ Motor Industry Training Organisation (Incorporated)
Accreditation and Moderation Action Plan (AMAP) reference / 0014

This AMAP can be accessed at

Special notes

1Legislation and publications relevant to this unit standard include but are not limited to – Health and Safety in Employment Act 1992; Land Transport Rules: Heavy-vehicle Brakes 2006, Rule 32015 (incorporates the Heavy Vehicle Brake Code); Heavy Vehicles 2004, Rule 31002; Vehicle Standards Compliance 2002, Rule 35001/1; Vehicle Inspection Requirements Manual (VIRM) – In-service Certification.

2Land Transport Rules are produced for the Minister of Transport by Land Transport New Zealand. These rules are available online at

The VIRM is published by Land Transport New Zealand and is available online at

3Definitions

Heavy vehicle refers to a motor vehicle that is of Class MD3, MD4, ME, NB, NC, TC or TD; or has a gross vehicle mass that exceeds 3500 kg and is not of a class specified in the Table of vehicle classes as listed from Land Transport New Zealand website

Service information may include but is not limited to – technical information of a vehicle, machine, or product detailing operation; installation and servicing procedures; manufacturer instructions and specifications; technical terms and descriptions; and detailed illustrations. This can be accessed in hard copy or electronic format and is normally sourced from the manufacturer.

Suitable tools and equipment means industry approved tools and equipment that are recognised within the industry as being the most suited to complete the task in a professional and competent manner with due regard to safe working practices.

4For this unit standard, it is essential that the practical assessment evidence is obtained in the workplace under normal workplace conditions.

Elements and performance criteria

Element 1

Inspect drum brakes on heavy vehicles and machines.

Performance criteria

1.1Safe working practices are observed throughout the task in accordance with legislative requirements.

Rangepersonal safety, safety of others, vehicle or machine safety, workshop safety, environmental safety, tools and equipment safety.

1.2Suitable tools and equipment are selected and used to enable the brakes to be inspected and repaired in accordance with service information.

1.3Brake drums are removed in accordance with service information.

1.4The operating mechanisms of drum brakes are inspected, and any defects noted, in accordance with service information.

Rangemay include but is not limited to – S-cam, Z-cam, wedge expanders, hydraulic slave cylinders, slack adjusters.

1.5Brake components are inspected for condition and compared against manufacturer specifications.

Rangemay include but is not limited to – hydraulic activation, pneumatic activation, mechanical activation;

drum ovality, drum condition, lining thickness, brake spring tension.

1.6Park brake activation is checked, and any defects noted, in accordance with service information.

Rangemay include but is not limited to – spring brakes, drive shaft brakes.

1.7Safety precautions are taken when repairing foundation brakes in accordance with legislative requirements.

Rangemay include but is not limited to – chocking vehicle, raising and supporting vehicle, cleaning.

Element 2

Repair drum brakes on heavy vehicles and machines.

Performance criteria

2.1Activating mechanisms are repaired in accordance with service information.

2.2The brake adjusters are repaired in accordance with service information.

2.3Drum brake components are repaired, replaced, and reassembled in accordance with service information.

2.4Park brake activation is adjusted in accordance with service information.

2.5Brakes are tested and perform in accordance with legislative requirements.

Please note

Providers must be accredited by NZQA, or an inter-institutional body with delegated authority for quality assurance, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.

Industry Training Organisations must be accredited by NZQA before they can register credits from assessment against unit standards.

Accredited providers and Industry Training Organisations assessing against unit standards must engage with the moderation system that applies to those standards.

Accreditation requirements and an outline of the moderation system that applies to this standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The AMAP also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.

Comments on this unit standard

Please contact the NZ Motor Industry Training Organisation (Incorporated) if you wish to suggest changes to the content of this unit standard.

 New Zealand Qualifications Authority 2018